Ultra-high performance Image Stabilisation L series telephoto zoom lens.
Incorporating Canon's second generation Image Stabilization technology, this telephoto zoom responds in as little at 0.5 seconds, while providing up to three stops of correction for camera shake. Its AF system has been refined for better response time and tracking speed. Plus, the new 8-blade circular aperture offers a more pleasing out-of-focus image. Constructed to pro standards, this fast zoom is also highly resistant to dust and moisture, too.
 
Features

• Image Stabilisation equals 3 stops in shutter speed
• High Image quality over the entire zoom range - using 4 UD lenses to correct residual chromatic aberration
• Dust and moisture resistance for high-performance in varied conditions
• Super-fast, silent autofocus due to inner focus design and ring USM
• Front lens does not move during focusing - ideal for use with circular polarising filters
• 1.4 metre minimum focusing distance over the full zoom range
• Compatible with EF 1.4x II and EF 2.0x II extenders - Image Stabilisation and autofocus work with the extenders in place and dust/water resistance is maintained